If $f (x) = 3 x - 7$ and $f (2 b) = 23$ , then $b$ is

5

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4

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6

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2

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Solution

The correct option is A $5$
Given, $f (x) = 3 x - 7$ and $f (2 b) = 23$
Putting $2 b$ in place if $x$ , we get
$f (2 b) = 3 (2 b) - 7 = 23$
$\Rightarrow 3 (2 b) - 7 = 23$
$\Rightarrow 6 b = 30$
$\Rightarrow b = 5$

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f : A \to B

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f (x) = ⎧ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎨ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ⎩ \begin{matrix} \frac{2^{x} + 2^{3 - x} - 6}{\sqrt{2^{- 2}} - 2^{1 - x}}; x > 2 \frac{x^{2} - 4}{x - \sqrt{3 x - 2}}; x < 2 \end{matrix}

f (x) = 3 x - 7

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c

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